This invention relates generally to electrical systems within automotive vehicles and specifically to a junction box electrically connected therein.
Before the introduction of junction box technology, wire harnesses for each automotive vehicle had to be individually tailored for particular vehicle options. Wire harnesses were extremely complex, required complex and costly splicing, and necessitated high labor costs throughout the manufacturing process.
With the introduction of junction boxes for connecting various wire harnesses together, the wire harness complexity and costs were reduced while the quality and reliability of the vehicle electrical system were enhanced. Two conventional constructions of internal electric current carrying circuits are known. The first uses alternating layers of conductive busbars and insulators. The busbars have male blades which protrude upward through slots in each insulating layer. Furthermore, external wire harnesses are connected directly to many of these busbar male blades. This first construction is generally shown in the following U.S. Pat. No. 5,207,591 entitled "Branch Junction Box and Busbars for Branch Connection" which issued to Ozaki et al. on May 4, 1993; U.S. Pat. No. 5,160,274 entitled "Branch Junction Box and Busbars for Branch Connection" which issued to Ozaki et al. on Nov. 3, 1992; U.S. Pat. No. 5,154,647 entitled "Electrical Junction Block for Automobile and a Method for Manufacturing the Same" which issued to Ishitani et al. on Oct. 13, 1992; and, U.S. Pat. No. 4,850,884 entitled "Controller-Including Wiring Apparatus for Automotive Vehicle" which issued to Sawai et al. on Jul. 25, 1989. The second traditional junction box construction consists of a plurality of printed circuit boards having male and female terminals projecting perpendicular therefrom. External wire harnesses and electronic modules can be connected to these various terminals. Such a construction is disclosed in the following U.S. Pat. No. 4,689,718 entitled "Programmable Junction Box" which issued to Maue et al. on Aug. 25, 1987; U.S. Pat. No. 4,703,397 entitled "Function Circuit Incorporating Type Wiring Device for Automobile" which issued to Minoura et al. on Oct. 27, 1987; and, U.S. Pat. No. 4,135,226 entitled "Automatic Junction Unit" which issued to. Kourimsky on Jan. 16, 1979. Moreover, the busbar and insulator construction and the printed circuit board construction are shown combined within the inside of a junction box in U.S. Pat. No. 4,355,853 entitled "Electrical Junction Box" which issued to Kourimsky on Oct. 26, 1982.
The preceding junction box designs have improved the reliability of electrical connections within the vehicle electrical system, however, these junction boxes have become increasingly complex to assemble, heavy and large due to the many added busbar and printed circuit board layers. Therefore, it is desirable to have an improved junction box that is relatively small, lightweight and of low cost while further having easy to assemble internal circuitry.